Closure for containers

ABSTRACT

A container and a closure therefore adapted to form a moisturetight seal and wherein the closure has a skirt that expands or contracts from the normal position to contact the sidewalls of the container as the top of the closure is flexed from one to another of two stable convex configurations.

United States Patent [72] lm cntor Egon Kern Graz, Austria 1211 Appl No.747,998 [22] Filed July 26, 1968 [45] Patented Feb. 2, 1971 [73]Assignce Dart Industries Inc.

Los Angeles, Calif. a corporation of Delaware [54] CLOSURE FORCONTAINERS 6 Claims, 12 Drawing Figs.

[52] US. Cl 220/60, 215/41 [51] Int. Cl B6Sd 43/10 [50] Field of Search220/60, 44; 215/41, 52

[56] References Cited UNITED STATES PATENTS 1,651.669 12/1927 Carpmael215/52 1,732,834 10/1929 Carpmael 215/52 Primary Examiner Joseph R,Leclair Assistant Examiner.lames R. Garrett Att0rneys-Paul R. Wylie,Robert P. Whipple and Harold R.

Beck 1 ABSTRACT: A container and a closure therefore adapted to form amoisture-tight seal and wherein the closure has a skirt that expands orcontracts from the normal position to contact the sidewalls of thecontainer as the top of the closure is flexed from one to another of twostable convex configurations.

PATENTEU FEB 2191: 3559 843 SHEET 1 BF 3 PATENIED FEB 2 IBYI SHE 0F 3PATENIED FEB 219m SHEET 3 0F 3 Fig. l2

Fig. II

CLOSURE FOR CONTAINERS The invention concerns a plastic storagecontainer and closure, which are quickly and simply operable and whichsimultaneously produces a reliable and lasting hermetic seal.

Plastic storage containers employing substantially airtight closureshave for some time been available for use in the preservation of alltypes of food. They generally have consisted of a bowl, cylinder orother similarly shaped vessel and a separate lid made of relativelysoft. flexible, but still elastic material. These lids normally employeda groove around their edges that could be pulled over the edge of thecontainer and which in most cases was slightly wider towards this upperedge. Correspondingly, these grooves are slightly more narrow in thedownward direction. Apart from this, of course, if such are to providethe desired tight seal, they must be so dimensioned that it sits astightly as possible on the container, the tightness of the sealtherefore being better, the tighter the lid fitted on the container.

It follows from the above that the lids of the above-mentionedcontainers must be stretched when they are placed on the container.Further depending upon this fit between the lid and the container theclosing of the container becomes a relatively troublesome andtime-consuming procedure. If, on the other hand, the fit is not tight,the desired airtight features may not be obtained. Such prior artcontainers are therefore adapted for improved sealing through aconstruction that enables the already closed container lid to bevigorously pressed down in the center, while the groove issimultaneously and temporarily loosened in any desired spot by liftingthe edge of the lid, the pressure exerted on the lid tends to expel theexcess air in the container. After the groove has again been pressedback and the lid has been released, the pressure in the container isreduced and consequently the lid is more forcefully pressed against theedge of the container by the outside surrounding air. Although suchcontainers are very satisfactory in most respects the additional,pneumatic closing effect is reduced over a period of time as air fromthe outside filters back into the container in addition, the describedmanipulative process of expelling air from the container is sometimesconsidered to be a nuisance to the female user. Also, since the user maybe unaware of the physical effect to be obtained, many of them may notperform this manipulative process, thus negating the value that isobtained from it.

In comparison, the present invention concerns a construction which notonly greatly simplifies the closing of the container, but alsoself-produces a permanent and reliable hermetic seal. This is achievedin the following manner:

The lid of the storage container in question is, in contrast to theknown containers of this type, not generally flat but assumes arelatively pronounced curved configuration. Since it is also made of aflexible, relatively soft, but still elastic material, the assumedcurvature can be easily reversed from concave to convex and vice versaas may be desired. Sealing the lid is accomplished by a simple, shortsleeve or flange which extends in an approximately vertical relationshipfrom the peripheral surface area of the lid. Depending upon thedirection in which the lid is pressed or flexed the sleeve or flangeassumes either a cylindrical or a conical attitude with respect to theplane of the peripheral edge of the surface area. In order to close acontainer of this invention, the lid is first manipulated so that itssleeve or flange assumes a cylindrical orientation. When so oriented,the lid can be loosely placed on the container or the bowl, whatever itsparticular shape, and then by pulling or pressing in the central area ofthe lid it can be forced to assume the opposite curvature. Thus, thesleeve or flange tends to settle either from the outside or on theinside against the wall of the container and in this way produces therequired, airtight seal.

Since the reversal of positions or shape of the surface of the lid(i.e., concave or convex) either enlarges or reduces the air spacewithin the container, a certain reduced pressure or excess pressure iscreated in the container, which acts in the sense of an additionalpressing of the sleeve against the container wall and thus reinforcesthe tightness of the closure. It is assured, however, that entirelyindependent of this, the deformation of the sleeve alone produces asufficiently hermetic seal which is reliable even if in the course oftime the additionally active pressure difference should be lost becauseof air migration into or out of the container.

The particular lid construction is dependent upon whether the lid is toseal internally or externally of the container.

The noted and additional advantages of the invention will become moreapparent upon reference to the following description, claims andappended drawings wherein:

FIG. I is a partial cross-sectional side view of one embodiment of thelid incorporating this invention;

FIG. 2 is a partial cross-sectional side view of a lid and containershowing the lid in its unsealed relationship thereon;

FIG. 3 is an enlarged partial cross section of FIG. 2 taken along line3-3;

FIG. 4 is an enlarged partial cross section similar to FIG. 3 exceptthat the lid is shown in its sealing relationship with the container;

FIG. 5 is a partial cross-sectional side view of another embodiment ofthe lid of this invention;

FIG. 6 is a partial cross-sectional side view of a lid and containershowing the lid in its unsealed relationship thereon;

FIG. 7 is an enlarged partial cross section taken along line 7-7 in FIG.6;

FIG. 8 is an enlarged partial cross section similar to FIG. 7 exceptthat the lid is shown in its sealing relationship with the container;

FIGS. 9 and 10 are enlarged partial cross sections similar to those ofFIGS. 3 and 4 showing a grooved container wall construction; and,

FIGS. 11 and 12 are enlarged partial cross sections similar to those ofFIGS. 7 and 8 showing a grooved container wall construction.

As indicated, FIGS. l4 illustrate an example of one of the preferredembodiments of the invention and FIG. I represents a section of the lidas it would appear upon removal from the pressure or extrusion mold atthe time of manufacture/The surface or top portion 2 of the lid iscurved upward (i.e., convex) and the sleeve or flange 3 which extendsaround and downwardly from the extreme edge of the surface 2 narrowsconically in the downward direction. In order to keep the sleeve 3sufficiently elastic, its wall must not be too thick, and in the crosssection it may become slightly thinner towards the downward end.

In order to close the container, the lid 1, unless it is not already inthis shape, is first pressed in to produce a concave shape as may beseen in FIG. 2. To accomplish this, the lid may be gripped in both handsand pressed in the downward direction from its upper side, with thethumb placed near the support 4 and handle 5. This operation may becarried out without any trouble even if the lid is of a large diameter.

Although the lid assumes the shape shown in FIG.- 2 it is so constructedthat its peripheral edge does not assume a shape thatis too stronglyopposed to the shape of the central surface area. In fact, it isadvisable that the initial shape of the surface or top portion 2 of thelid is not circularly domed so as present a ball shape, but that it begiven a more conical shape, as shown in FIG. 1.

The shape of the lid according to FIG. 2 has a sleeve 3, which, as isseen, approximates a cylindrical configuration. In this form, the lidcan be easily placed on the container 6, the walls of which at theirupper open ends are also substantially cylindrical.

Once the lid has been placed on the container, its peripheral edge isheld down with one hand while the other hand grips and pulls thering-shaped handle 5 upward. Lids of large diameter containers, if theyare to be pulled upward into the convex position, may be held around aportion of the edge with one hand while the other hand is used tomanipulate the handle in a manner similar to that described.

When the lid 1 is pulled up, it again assumes the convex shape shown inFIG. 1 and in so doing settles sleeve or flange 3 at its lowermostextremity tightly against the outer face of the wall of the bowl 6. Thismay best be seen in FIG. 4. which illustrates the lid and container in asealed relationship Since in operation the sleeve or flange 3 is insubstantially all around sealing contact with the wall of bowl 6 evenbefore the lid has been entirely pulled up, and a reduced pressure formssimultaneously in the inside of the container. Because of this reducedinside pressure the sleeve 3 is subjected to the additional sealingpressure that the air exerts on the outside of the sleeve.

The enlargement to the interior of the container that is produced by thepulling up of the lid creates a pressure differential with a reducedinside pressure that has been mentioned. Thus, in addition to therebeing exterior pressure exerted on the sleeve, such pressure is alsoexerted the surface or top portion 2 of the lid tending to press the lidagainst the uppermost edge of the bowl 6. If the edge of the bowl andthe interior of the peripheral edge of the lid were completely smooth inthis location, passage of air into the container would be preventedduring the initial phase of the lid inversion process. If such were thecase, however, the pressure difference produced would generally precludethe inversion of the lid. In order to prevent this, either the undersideof the lid at its peripheral edge adjacent flange 3 or the uppercontainer edge should be constructed with radial or similar grooves toenable some air to pass. In the example shown in the FIGS. such grooves7, are arranged on the underside of the lid surface 2. As can be seenthese grooves 7 are also continued into the inside of sleeve 3 in theform of the short grooves 8. These grooves function to facilitateintroduction of a sufiicient amount of air as the sleeve 3 is pressedaround the bowl or container 6, so that an effective seal may beproduced. FIGS. 3 and 4 each show one of the grooves 7 and 8 in asectional view, however, showings thereof have been omitted from theremainder of the cover for the sake of clarity.

In the embodiment shown in FIGS. 1-4, the grooves 7 and 8 should beconstructed as to number and shape, so that the air cannot penetrate tooeasily. This will enhance the ease of operability of this lid in that itneeds to be held with the fingers only in a few places. I

Inversion of the lid is considerably facilitated by the fact that thehandle of the lid 5, which as has been mentioned, is shaped as a ringwith a crooked threaded stem which attaches the ring to the lid so thatin its assembled condition with the lid it is asymmetrical oreccentrically located with respect to the center of the lid as is shownin FIGS. 1 and 2. If this was not the case, the lid would initiallyoppose the inversion process rather strongly and then would suddenly popinto the opposite curvature. This, however, would not only make theinversion troublesome, and might, because of the jerky movement, preventthe lid from becoming firmly seated upon the container. Because of theasymmetrical form and position of the handle 5, the support 4 tends tobe twisted angularly when the handle is pulled and thus without aconscious effort quite naturally initially begins the inversion of thelid in one half of its surface.

From this start it spreads like a wave successively across the entirelid surface is completed in seconds and requires hardly more than onemovement of the hand. The inversion is thus effected in a trouble-freeand convenient manner with an even movement, corresponding to the influxof air through the grooves 8 and 7.

In order to reinforce the hermetic closure of the container, either thesleeve 3 of the lid or the container can be equipped with somering-shaped narrow bulges along the contact surface between the two.FIGS. 3 and 4 illustrate a model which has such narrow bulges 9 on thesleeve 3.

In order to open the container, the seal need only be broken by pressingthe handle downward after which the lid may be lifted off. Theasymmetrical shape and position of the handle 5 here also produces asimilar wavelike effect as is described except in an opposite sense. Ofcourse, once the container has been opened, the lid again assumes theshape required to repeat the closing step.

A second embodiment of the storage container is shown in FIGS. 5--8 andis similar in its operation to 5-8 described above. In this instance,however, the lid in its tension-free initial shape is curved downward,as shown in FIG. 5. The applicable discussions relative to lid curvatureare analagous to what has been said concerning the embodiment shown inFIGS. 14. The sleeve 3 widens conically in the downward direction contrato the previous embodiment and, of course. the curved portions of thelid are reversed with respect to the open and closed positions. Inaddition, here the sleeve 3 is positioned inwardly of the outermostperipheral edge of the lid surface or top potion 2, thus leaving anedging 10. This edging, after the lidrhas been inverted upwards, isplaced on the upper edge of container 6 with the sleeve 3 lying adjacentthe inside surface of the wall of the container. FIGS. 6 and 7 clearlyshown this arrangement in which the lid loosely rests on the container.FIGS. 7 and 8 also show that the grooves 7 which permit the necessaryexchange of air during opening and closing of the container, however,here these are arranged along the underside of the edging l0 and thegrooves 8 from which the grooves 7 on the sleeve 3 are continued, arecorrespondingly located on the outside sleeve surface. In thisparticular embodiment the grooves 7 and 8 can be more numerous or deeperthan is practical with the earlier described embodiment.

In this instance to achieve a substantially airtight seal between thecontainer and lid 1, the lid is pressed downward by way of the handle 5,so that the sleeve 3 settles tightly against the interior surface of thewall of the container 6, as can be best seen in FIG. 8. In view of thefact that the volume within the container is somewhat reduced thereby,an incremental excess pressure is created in the interior of thecontainer. In order to assure that this excess pressure does not liftthe lid off the container, the sleeve or flange 3 of this embodiment hasa projection 11 with the profile of a nose, which during lid inversionis adapted to engage the underside of projection 12 at the wall of thecontainer 6. Again closing can be accomplished in a particularly quickand convenient manner but it still should be done with a relativelysmooth movement, Without such a smooth movement the possibility existsthat the lid, especially on the side away from the handle 5 may jump outof the container before its projection 11 has a chance to engage theprojection 12. The excess pressure created by the closing inversion,here also supports the tightness of the closure which has already beenachieved by the concave formation of the sleeve.

In order to show another alternative, FIGS. 7 and 8 show the bulges 9not on the closing sleeve 3, but on the inside upper edge of thecontainer wall rather than on the sleeve 3.

Further, FIGS. 5 and 6 illustrate a handle 5 on the lid and its support4 in a manner which pennits the handle ring 5 to be folded down afterclosing, a feature that may be desirable to effect space-saving.

The latter described embodiment of the present storage container,besides the fact that it requires less space, has a greater safetyadvantage in comparison to the first embodiment (FIGS. 1-4). Thisadvantage is provided not only by the engageable elements 11 and 12, butalso because it cannot be accidentally opened by unintentionallyexerting pressure on the lid. This maybe important when the container isused for travel and camping, etc. It should be noted, however, that theprojection 12 which, butts into the interior of the container 6 maycreate difficulties in manufacturing if the container and the lid, aremade of a hard material rather than a flexible material.

Thus, it is advantageous to manufacture the embodiment shown in FIGS.5-8 from a flexible material. If, however, the containers are made of ahard material, for example of metal, glass porcelain, etc. it may bemore suitable to employ the construction of FIGS. 1-4.

In conclusion, it should be pointed out that the described closures maybe used for other than circular containers, so long as thecontaineredges are sufficiently rounded and the lateral walls areslightly concave. For rectangular or similarly shaped containers thesleeve of the lid can give only slightly in the corner areas and the lidin the initial or sealing shape can be only slightly angled in thislocation, while in the center of the sides it can be just as slanted asis the case with circular containers. Further, since the pressure tendsto be equally distributed along the sleeve, a reliable sea] is stillassured around the whole circumference of even a rectangular sleeve Thecenter portion of the curved lid surface in this instance will assume aball shape.

I claim:

1. A container for the storage of foodstuffs and comprising a bowl and aremovable and deformable lid, said bowl including an upper open endedwall construction that is of substantially cylindrical configuration,said lid being comprised of a flexible top portion which is movable totwo positions of stable convex configuration and from which theredepends a flange that is adapted to assume a cylindrical configurationin one of said two positions of said flexible top portion such that itcan be placed upon said bowl with the flange in telescoping relationwith the upper open ended wall construction and is further adapted toassume a conical shape in the other of said two positions of saidflexible top portion such that the flange tightly presses against theupper open ended wall construction, a plurality of connected groovesextending radially in the underside of said flexible top portion anddownwardly along the sealing side of said flange to a point oftermination immediately below the interconnection between said flangeand flexible top portion, and a handle attached to the outer face of theflexible top portion so that it may be employed to move said top portionfrom each to another of said positions.

2. A container according to claim 1, wherein said flange furtherincludes a projection that engages a mating projection in the upper openended wall construction of said bowl when the lid is in sealedrelationship with said bowl.

3. A container according to claim 1, wherein said handle is hinged insuch manner that it can be rotated to an out of the way position.

4. A container for the storage of foodstuffs and comprising a bowl and aremovable and deformable lid, said bowl including an upper open endedwall construction that is of a substantially cylindrical configurationand that has formed therein a plurality of grooves extending radiallyacross the upper edge of the wall and downwardly in the sealing sidethereof to a point immediately below the upper edge, said lid having aflexible top portion which is movable to two positions of stable convexconfiguration and from which there depends a flange that is adapted toassume a cylindrical configuration in one of said two positions of saidflexible top portion such that it can be placed upon said bowl with theflange in telescoping relation with the upper open ended wallconstruction and is further adapted to assume a conical shape in theother of said two positions of said flexible top portion such that theflange tightly presses against said upper open ended wall construction,and a handle attached to the outer face of the flexible top portion sothat it may be employed to move said top portion from each to the otherof said positions.

5. A container according to claim 4, characterized in that the topportion of the lid in its position in which the depending flange iscylindrical is upwardly convex from the bowl rim and the dependingflange is disposed at the periphery of the lid and externally gripsaround the rim of the bowl.

6. A container according to claim 4, characterized in that the topportion of the lid in its position in which the depending flange iscylindrical is convex downwardly from the bowl rim and the dependingflange is disposed radially inwardly from the periphery of the lid andreposes inside the rim of the bowl and has at its lower end anexternally projecting protrusion which lockingly grips under acorresponding protrusion of the inner face of the side wall of the bowlwhen the container is closed.

1. A container for the storage of foodstuffs and comprising a bowl and aremovable and deformable lid, said bowl including an upper open endedwall construction that is of substantially cylindrical configuration,said lid being comprised of a flexible top portion which is movable totwo positions of stable convex configuration and from which theredepends a flange that is adapted to assume a cylindrical configurationin one of said two positions of said flexible top portion such that itcan be placed upon said bowl with the flange in telescoping relationwith the upper open ended wall construction and is further adapted toassume a conical shape in the other of said two positions of saidflexible top portion such that the flange tightly presses against theupper open ended wall construction, a plurality of connected groovesextending radially in the underside of said flexible top portion anddownwardly along the sealing side of said flange to a point oftermination immediately below the interconnection between said flangeand flexible top portion, and a handle attached to the outer face of theflexible top portion so that it may be employed to move said top portionfrom each to another of saiD positions.
 2. A container according toclaim 1, wherein said flange further includes a projection that engagesa mating projection in the upper open ended wall construction of saidbowl when the lid is in sealed relationship with said bowl.
 3. Acontainer according to claim 1, wherein said handle is hinged in suchmanner that it can be rotated to an out of the way position.
 4. Acontainer for the storage of foodstuffs and comprising a bowl and aremovable and deformable lid, said bowl including an upper open endedwall construction that is of a substantially cylindrical configurationand that has formed therein a plurality of grooves extending radiallyacross the upper edge of the wall and downwardly in the sealing sidethereof to a point immediately below the upper edge, said lid having aflexible top portion which is movable to two positions of stable convexconfiguration and from which there depends a flange that is adapted toassume a cylindrical configuration in one of said two positions of saidflexible top portion such that it can be placed upon said bowl with theflange in telescoping relation with the upper open ended wallconstruction and is further adapted to assume a conical shape in theother of said two positions of said flexible top portion such that theflange tightly presses against said upper open ended wall construction,and a handle attached to the outer face of the flexible top portion sothat it may be employed to move said top portion from each to the otherof said positions.
 5. A container according to claim 4, characterized inthat the top portion of the lid in its position in which the dependingflange is cylindrical is upwardly convex from the bowl rim and thedepending flange is disposed at the periphery of the lid and externallygrips around the rim of the bowl.
 6. A container according to claim 4,characterized in that the top portion of the lid in its position inwhich the depending flange is cylindrical is convex downwardly from thebowl rim and the depending flange is disposed radially inwardly from theperiphery of the lid and reposes inside the rim of the bowl and has atits lower end an externally projecting protrusion which lockingly gripsunder a corresponding protrusion of the inner face of the side wall ofthe bowl when the container is closed.